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- //
- // Copyright 2005-2007 Adobe Systems Incorporated
- //
- // Distributed under the Boost Software License, Version 1.0
- // See accompanying file LICENSE_1_0.txt or copy at
- // http://www.boost.org/LICENSE_1_0.txt
- //
- #include <boost/gil/extension/io/jpeg.hpp>
- #include <algorithm>
- // This test file demonstrates how to use packed pixel formats in GIL.
- // A "packed" pixel is a pixel whose channels are bit ranges.
- // Here we create an RGB image whose pixel has 16-bits, such as:
- // bits [0..6] are the blue channel
- // bits [7..13] are the green channel
- // bits [14..15] are the red channel
- // We read a regular 8-bit RGB image, convert it to packed BGR772, convert it back to 8-bit RGB and save it to a file.
- // Since the red channel is only two bits the color loss should be observable in the result
- //
- // This test file also demonstrates how to use bit-aligned images - these are images whose pixels themselves are not byte aligned.
- // For example, an rgb222 image has a pixel whose size is 6 bits. Bit-aligned images are more complicated than packed images. They
- // require a special proxy class to represent pixel reference and pixel iterator (packed images use C++ reference and C pointer respectively).
- // The alignment parameter in the constructor of bit-aligned images is in bit units. For example, if you want your bit-aligned image to have 4-byte
- // alignment of its rows use alignment of 32, not 4.
- //
- // To demonstrate that image view transformations work on packed images, we save the result transposed.
- using namespace boost;
- using namespace boost::gil;
- int main() {
- bgr8_image_t img;
- read_image("test.jpg",img, jpeg_tag{});
- ////////////////////////////////
- // define a bgr772 image. It is a "packed" image - its channels are not byte-aligned, but its pixels are.
- ////////////////////////////////
- using bgr772_image_t = packed_image3_type<uint16_t, 7,7,2, bgr_layout_t>::type;
- bgr772_image_t bgr772_img(img.dimensions());
- copy_and_convert_pixels(const_view(img),view(bgr772_img));
- // Save the result. JPEG I/O does not support the packed pixel format, so convert it back to 8-bit RGB
- write_view("out-packed_pixel_bgr772.jpg",color_converted_view<bgr8_pixel_t>(transposed_view(const_view(bgr772_img))), jpeg_tag{});
- ////////////////////////////////
- // define a gray1 image (one-bit per pixel). It is a "bit-aligned" image - its pixels are not byte aligned.
- ////////////////////////////////
- using gray1_image_t = bit_aligned_image1_type<1, gray_layout_t>::type;
- gray1_image_t gray1_img(img.dimensions());
- copy_and_convert_pixels(const_view(img),view(gray1_img));
- // Save the result. JPEG I/O does not support the packed pixel format, so convert it back to 8-bit RGB
- write_view("out-packed_pixel_gray1.jpg",color_converted_view<gray8_pixel_t>(transposed_view(const_view(gray1_img))), jpeg_tag{});
- return 0;
- }
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